Plasma gasification reactors (sometimes referred to as PGRs) are a type of pyrolytic reactor known and used for treatment of any of a wide range of materials including, for example, scrap metal, hazardous waste, other municipal or industrial waste and landfill material, and vegetative waste or biomass to derive useful material, e.g., metals, or a synthesis gas (syngas), or to vitrify undesirable waste for easier disposition. In the present description “plasma gasification reactor” and “PGR” are intended to refer to reactors of the same general type whether applied for gasification or vitrification, or both. Unless the context indicates otherwise, terms such as “gasifier” or “gasification” used herein can be understood to apply alternatively or additionally to “vitrifier” or “vitrification”, and vice versa.
PGRs and their various uses are described in, for example, U.S. Pat. No. 7,632,394 by Dighe et al., issued Dec. 15, 2009, entitled “System and Process for Upgrading Heavy Hydrocarbons”; U.S. Patent Application Publication No. 2009/0307974 by Dighe et al., entitled “System and Process for Reduction of Greenhouse Gas and Conversion of Biomass”; and U.S. Patent Application Publication No. 2010/0199557 by Dighe et al., entitled “Plasma Gasification Reactor”, all of which are incorporated by reference herein for their descriptions of PGRs and methods practiced with them.
Heat from an electric arc can be fed into a cupola, furnace, or other reactor vessel to enhance the operation thereof by providing a very hot gas stream which may be either oxidizing or reducing and can also be mixed with particulate material. The electric arc can be produced in a plasma torch in which the electric arc ionizes the gas which is blown out of the end of the torch producing a hot gas stream which generally operates in the range of, for example, 10,000° F. or 5,538° C.
Typically such reactor vessels must be preheated during a start-up process. Burners for natural gas or other combustible fluids may be included to perform the pre-heating. Such burners may be removed after pre-heating is completed. Such burners may also require dedicated ports on the reactor for installation and removal and can pose a challenge operationally to do so safely. It would be desirable to have an alternative way to preheat the reactor.